The technology relates generally to user interfaces that control devices, such as radios, automobiles, navigation systems, and other types of devices.
User interfaces for controlling equipment, such as a car radio, are well known. Such interfaces may comprise various knobs, switches, and on-screen icons and buttons that control the selection of radio volume, station, and audio enhancements. The user typically makes selections by pressing the buttons, knobs, or icons on a touch-screen display. A user interface for controlling the speed of an automobile may include one or more switches or levers that are pressed to activate cruise control or to accelerate to a higher speed. A user interface for controlling a navigation system may include various icons and on-screen selectors for selecting a destination, re-routing to avoid a traffic condition, or requesting more information about a particular point of interest. A user interface on a mobile device such as a mobile phone may include a touch-screen display allowing numerals to be selected and buttons for initiating and terminating a telephone call.
It would be desirable to permit control of a user interface on the basis of environmental cues, such as visual cues like a traffic sign or information sign.